Door opening mechanism



FIG 5/ Y/ j; v A I. 4

July 20, 1965 D. D. RITCHEY 3,195,330

DOOR OPENING MECHANISM Filed Dec. 15, 1961 INVENTOR DONALD DALE RITCHEY United States Patent 3,195,889 DOOR OPENING MEQHANISM Donald D. Rite-hey, Albuquerque, N. Mex. (701 Elm St., Boulder City, Nev.) Filed Dec. 15, 1%1, Ser. No. 159,608 4 Claims. (Cl. 268-72) The present invention relates to means to open a door and more particularly to means to open a door gradually during the initial opening movement particularly where the door is held by latching mechanism which has a relatively high holding power in the fully closed position and where the holding power rapidly drops off as the door is opened.

Heretofore conventional latch mechanism including magnetic catches have been used to hold a door closed to prevent unintentional opening of a door, and it is important that the force holding the door closed is sufficient to maintain the door closed even though some forces tend to open the door. However, if the force holding the door closed is sufiicient to securely hold the door closed, a correspondingly large force is required to open the door. In many door installations this opening has depended on a direct pushing or pulling force on the door or on a handle fixed to the door. It has been observed that when a catch or latch of this type becomes released by the direct force, the direct force at the instant of release is so great that before the operator could reduce the direct opening force the door suddenly open with the direct force overcoming the inertia of the door, resulting in the door being excessively rapidly opened and being so forcefully opened that if a person were carrying a filled dish, there would be danger of spilling the contents of the dish because of the sudden change in movement at the instant the latch became suddenly completely released and while the large opening force was still being applied.

An object of the present invention is to provide a door opening structure'which provides for a large mechanical advantage at the time the door is initially opened against the force of the latch, and a reducing mechanical advantage as the door continues to be opened until the mechanical advantage becomes zero when the door is completely released from the action of the latch mechanism.

Another object is to provide a simple lever mechanism having a varying mechanical advantage for applying a force in controlled amounts.

A further object is to provide a door closure operating structure which prevents sudden jerky operation thereof in both opening and closing.

Other and further objects will be apparent as the description proceeds and upon reference to the accompanying drawing wherein:

FIG. 1 is a fragmentary perspective of the interior of a cabinet showing a hinged door and one form of lever opening means operated by a knob on the exterior of the door.

FIG. 2 is a horizontal section taken on line 22 of FIG. 1 showing the lever in its inoperative position when the door is completely closed.

FIG. 3 is a similar view with the door opened beyond the action of the illustrated magnetic catch and showing the lever system at the limit of its opening movement.

. FIG. 4 is an elevation of the rear surface of a modification of a fragment of the door and lever of FIG. 5 showing the communicating grooves receiving the lever.

FIG. 5 is a similar view of a fragment of a door and frame taken substantially on line 55 of FIG. 4 showing an L-shaped lever mounted in a communicating groove and rabbet on the interior of the door on two loose pivots "Ice adjacent the ends of the legs and showing an adjustable abutment on the frame for obtaining the proper operating relation of the parts.

FIG. 6 is a perspective view of a further modification of the door opening mechanism of the present invention, shown in full lines, and in operative relation to a door and frame shown in phantom lines.

Briefly, the present invention includes a system for opening a closure in which the mechanical advantage varies from a maximum at initial opening with the mechanical advantage reducing after the initial opening is accomplished and specifically includes a lever having a rocker type of fulcrum to vary the effective length of the force applying portion of the lever, and the force receiving portion of the lever.

Referring more particularly to the drawing, a cabinet having side walls 10 and 11, top wall 12, and bottom wall 13, has a door 14 mounted by hinges 14A with the door held in closed position by a latch shown as being a magnetic catch 15 adjustably mounted on wall 10 by screws in slots, said catch having two magnet poles cooperating with a keeper plate 16 mounted on the door 14. The catch 15 is mounted so the door is effectively held closed in a known manner.

The usual means of opening a door held in closed position by a magnetic catch or a friction latch or other latch means of a yieldable nature is to apply a direct force on the door by means of a fixed handle and such direct force is frequently of such a high value that at the instant the door is opened and the latch and keeper separate, the force applied by the person opening the door is so excessive that the door suddenly opens causing a person having objects in his hands such as filled bowls to jostle the bowls and spill the contents. The latch to perform its function must be arranged to require sufficient force to hold the door closed but when the latch is adequate to hold the door closed, the opening force becomes excessive with the above results and, therefore, the use of fixed handles on the door has not been satisfactory.

The side wall or latch jamb 10 is provided with a rabbet 17 which receives the force applying end of a knee curved lever 18 pivoted on the interior of door 14 by means of a screw 19 loosely received in an enlarged aperture 20 in the knee of lever 18 so that the lever rocks about the curve at the knee causing the effective fulcrum to vary from a point X to a point Y as the lever is operated from the position shown in FIG. 2 Where the door is completely closed to the position shown in FIG. 3 in which the lever has completed its operation and released the latch from the field of action thereof.

To operate the door from the exterior of the cabinet the one or force receiving end of the lever 18 is provided with an aperture 21 receiving a screw element 22 freely passing through a passage 23 in door 14 and on which screw element 22 an operating knob element 24 is mounted at a suitable distance from the lever 18 by means of the screw threads so that the lever 18 can move freely from the position of FIG. 2 to the position of FIG. 3 in opening the door. The screw may be loose relative to lever 18 as shown.

In the modification of FIGS. 4 and 5 similar parts are identified by the same reference numerals, but the lever 18A is modified to include a second leg 25 at an angle to the lever 18 forming an L-shaped lever and the outer end of the second leg 25 is loosely pivoted to the door 14 on a pivot screw 26, the L-shaped lever being received in a recess including a rabbet 27 at the lower edge of the door 14 and a communicating groove 28 extending at the angle of the L-shaped lever thereto. The force applying end 29 of the lever 18 cooperates can reach around the edge of'thedoor with his fingers'and engage the lever 18A near the. force receiving end 1813 thereofwhich force receiving end 18B'serves as a handle.

from the hold of attraction of any part of the door, the door in closing firstcauses the end 29 of the lever 18 to engage the abutment on the door frameand continued closing of the door Causes the lever 18 tomove from a position similar to that of FIG. 3 to a position similar to that of 'FIG. 2. Evidently, some of V the kinetic energy of the moving door is absorbed in cansing lever 18to. suddenly move from the position of FIG. 3

It will be evident that a portion ofthe bottom-wall 13 a may be cut away as shown at 31, providing access to the lever 18A near the junction with leg 25, The effective movement of lever 18A, 2 -is about the axis of pivot 26 and the moving fulcrum trom-point'X to point Yand generally about a line between screws 19 and 26. p

v In the modification of FIG. 6, where the same partsare identified with similar numerals, the door 14 and a portion of the top and'side wallsl12 and 10, respectively, are shown in phantom line. 'An'exteriorly' mounted handle 32'oper-l atesthe lever 18 mounted onthe inner surface of the door 14 on the loose-fitting screw 19 and the force applying end 29 of thelever 18 reacts: against the adjustablescrew 39 mounted inthe edgeof the latchjamb 10. Fixed; to the force receiving end of thelever is a bolt element 33 pass- .ing throughian aperture in lever 18 and having its head engagedwith one surface of the lever 18'and a nut 34 thereon reacting with the head of thebolt 33 clamping the ,lever 18 -securely"therebetween. The bolt 33 is threaded into a threaded bore in a generally curved handle 32 and ispreferablysecurely fixed thereto by a lock nut;

35 thereby providing a strut elementmakinghandle 32 and lever 18 into an -L'-shaped lever arrangement. One end of the handle 32 is loosely pivoted tothe outersurface of the 'doorby. means of a screw 36 so thatthe leverarrang'ement 18:32 pivots about pivot screws 19- andf36' similar to the pivotal action of the modification of FIGS.

to theposition of FIG. 2 to prevent excessive rebound which'in prior art structures frequently would cause a door to reopen. v t t Regardless of the scientific explanation for this action, it has been demonstrated in a working sample of the inventionthat'when the lever is in the position of FIG. 3 at the time the door is closed, the do'or remains'close'd upon slamming, butif the .lever18 is in the position of FIG.,2'at the time of slamming the door rebounds open,

1 and therefore the prese-ntinvention overcomes this disadvantage of prior artstructures. r e l Upon forcefully closing'the. door, it has also been ob- "served that theop'ening device of: the present invention assumes the position relative to the door shown in FIGJ'3 before the door is closed, and this appears to be due to the inertia of the parts. The acceleration of the door as it is moved from its fast open position rapidlytoward the closed position of FIG. 2,'the parts of the opener tend to remain at rest' as the .door is moved and the parts are arranged to remain in thisposition of FIG. 3'until' the door is decelerated upon; closing'an'd the opener device is restored to the position ofJFIG- 2 relative to the door.v

Consequently, as the door moves to its final closed condition; the openingdevice must be accelerated thereby reducing any'tendencyof the door to rebound because of the-absorption of energy of the moving door and transfer f of such energy to the. opening device including the lever 4 and S-about pivotscre'ws 19 'and'26. -The' handle 32' a may haveanupward extension 37 for facilitating operation by suitable engagement of any projection therewith so that a person may have his hands full and still be able to operate the lever handle 32 byjhooking a single finger or by hooking any projection on the object being carried and smoothly operating the door against the action 'of the latchwithout sudden release of the retaining force of the latch. e

the door opens smoothly and by the time the lever cannotmove relative to the, door the force ofIthemagnetic latch o'r'other latch has no -materialelfect on the door and therefore theoperator can accurately control the door latch employed whether such latch is a friction, or spring pjressed detenttype and accordingly the invention can be of universal use.j The adjustment obtained by means of abutment screwfit) and bolt 33 or screw 22 provide a solution for practic'ally any conditionsencountered Inclosirlg the door, theleverlS andthe elements se-, cured thereto perform a snubbing'function preventing r e-' bound of thea doorwhich rebound usually prevents the latch from retaining the door-closed, particularly when the door is slammed shut such asthe door of .a refriger ator.

maintain the sai d. handle 32 and leg 2 ina position in whiclifthe 'lever 18 will remain in a position similar-to that:

R It will be noted that the arrangement of the handle V v and the leg'25 are such that the force of gravity tendstoand handle arrangement'thereof. 1 1 It will be evident that various changes can be madein the practice of, the, invention'within the valid scope of the appended claims. 2 J l What is claimedis: 1. A door opening device having a high'original mechanical advantage changingto a reducing mechanical advantage, comprising a door'frame and a doora movably' mounted 'on the door frame, a lever mounted on the door he understood that the rshapeof the lever 18 and i the position ofiapplying force to thetlever 18 is such that and movable about an effective fulcrum in the direction of movement of the door'and having an operating handle positively connected directly to one end of the lever and 'spaced'a substantial distance from the other end of the lever and'movable relative-to the door in the direction of door movement with the handle located on oneside of a door, a variable'force applying portion at the other end of the lever'engaging an element fixed to the door frame at the opening edge off the door, articulated mounting means between the ends of'the lever movably "supporting the lever including the handlefor rocking movement of the lever whereby the effective 'length'of the moment arm between the handle and the effective fulcrum is many t mes greater than the length between the forceflapplying portion of the; lever and the efiectiv'e fulcrum, said effectivejfulcrum including cam means for varying the moment arm between the'eifective fulcrum and the force applying portion of the lever to "cause the mechanical advantage to continuously, vary from a high mechanical ad vantage to 'a small mechanical'advantage as the door is opened ffur-ther, readily yieldable means including said lever and sa1d handle retaining the leverin" the door open position whereby when the ,door is being closed, the lever shown, in FlG. 3,, when the door is open... Therefore,

when the door is closed by theusual slamming'of the door' by forceful cont-actor aportion. of a persons body'against receives the force of the closing door at the said; force applying portion of the lever absorbing at least some of the momentum of the closing movingjdoor with decreasing mechanical advantageand increasing velocity whereby'the deceleration ofthe moving door results in accelera-- tion :of the lever thereby. reducing 'the impact of the final movement of the closing' door and 'thereafter'producing a 'fprther force in ;the closing direction after the dooris closed and the lever is abruptly stopped. a i

2. The invention according to claim 1 in which an element is positively connected at one of its ends to the said one end of the lever and freely passes through the door and the handle is positioned on the side of the door opposite the lever and is secured to the other end of the element.

3. The invention according to claim 1 in which the lever has a leg connected by one of its ends to said one end of the lever and extends at an angle to the lever, the

one end portion of the lever and the one end portion of the 10 leg providing the handle, the other end of said leg being pivotally mounted on the door.

4. The invention according to claim 1 in which an element passes freely through the door and is fixed at one of its ends to said one end of said lever and the handle is a strut fixed to the other end of said element with the free end of the strut element being pivotally connected to the door.

References Cited by the Examiner UNITED STATES PATENTS 1,396,373 11/21 Laskowski 220-43 5 2,422,770 6/47 Blum 268-72 2,659,115 11/53 Anderson et al 2069 2,970,857 2/61 Squire 292251.5

FOREIGN PATENTS 661,420 6/ 38 Germany. 1,238,808 6/60 France.

213,097 3/24 Great Britain.

HARRISON R. MOSELEY, Primary Examiner. 15 JEROME SCHNALL, Examiner. 

1. A DOOR OPENING DEVICE HAVING A HIGH ORIGINAL MECHANICAL ADVANTAGE CHANGING TO A REDUCING MECHANICAL ADVANTAGE, COMPRISING A DOOR FRAME AND A DOOR MOVABLY MOUNTED ON THE DOOR FRAME, A LEVER MOUNTED ON THE DOOR AND MOVABLE ABOUT AN EFFECTIVE FULCRUM IN THE DIRECTION OF MOVEMENT OF THE DOOR AND HAVING AN OPERATING HANDLE POSITIVELY CONNECTED DIRECTLY TO ONE END OF THE LEVER AND SPACED A SUBSTANTIAL DISTANCE FROM THE OTHER END OF THE LEVER AND MOVABLE RELATIVE TO THE DOOR IN THE DIRECTION OF DOOR MOVEMENT WITH THE HANDLE LOCATED ON ONE SIDE OF A DOOR, A VARIABLE FORCE APPLYING PORTION AT THE OTHER END OF THE LEVR ENGAGING AN ELEMENT FIXED TO THE DOOR FRAME AT THE OPENING EDGE OF THE DOOR, ARTICULATED MOUNTING MEANS BETWEEN THE ENDS OF THE LEVER MOVABLY SUPPORTING THE LEVER INCLUDING THE HANDLE FOR ROCKING MOVEMENT OF THE LEVER WHEREBY THE EFFECTIVE LENGTH OF THE MOMENT ARM BETWEEN THE HANDLE AND THE EFFECTIVE FULCRUM IS MANY TIMES GREATER THAN THE LENGTH BETWEEN THE FORCE APPLYING PORTION OF THE LEVER AND THE EFFECTIVE FULCRUM, SAID EFFECTIVE FULCRUM INCLUDING CAM MEANS FOR VARYING THE MOMENT ARM BETWEEN THE EFFECTIVE FULCRUM AND THE FORCE APPLYING PORTION OF THE LEVER TO CAUSE THE MECHANICAL AD- 